2012/03/15

A look back: An amazingly bad gun design

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Back in 1896 the German army introduced the 77 mm light field cannon 96; it was a normal cannon design with a recoiling carriage. The latter feature is and was widely criticized for being obsolete: The famous French 'soixante-quinze' revolutionised field artillery with the first recoiling barrel carriage which did not require to reset and aim the carriage after every shot (this made a shield practical, too). The 77 mm Fk 96 was consequently rebuilt with a recoiling barrel design carriage and renamed with suffix "n.A." (AFAIK = neue Art; new model).

The common literature on the new version supposes that it was now a useful field piece, albeit less useful than about as heavy and about as expensive 105 mm field howitzers.

I am quite sure that this falls well short of being an accurate appraisal.

This gun was in use prior to the First World War and during it and a successor design was introduced in 1916.

The list of shortcomings was huge, let's begin with the major difference with its successor type: The maximum gun elevation. 77 mm Fk 96 n.A. had -13/+15° gun elevation, 77 mm Fk 16 had -10/+40° gun elevation. The maximum range can be achieved at about 43° (would be 45° if there was no drag). The old design simply threw away a sizeable chunk of its potential range. Why? Well, the importance of indirect fires was not fully understood before WW1. It was known that the shell is more effective if it descends near-vertically, it was known that you cannot really do much with 15° elevation if you're in an area with woods or on rolling terrain and it was known that indirect fires were valuable not the least thanks to superior survivability (otherwise there would have been no field howitzers). Still, the maximum elevation of the cannon was only suitable for flat lands, preferably with hard and even soil (for bouncing shots with delay fuse).

Next issue; the gun traverse. The carriage was such a primitive box trail carriage that the traverse was only 8°. 8°! This basically means you need to turn the entire carriage after every shot unless your target is stationary. This, BTW, was supposed to be a solved problem with the introduction of the barrel recoil. The successor was even worse; 4°! Clearly, nobody was anticipating or understanding the utility of being able to react quickly to calls for indirect fires and was in a position of decisive influence at the same time.

Another weakness or such cannons at that period was the widespread use of shrapnel ammunition. This meant the shells needed elaborate time fuses for any hope of accurately timed shrapnel release. A bit too early or a bit too late and the shrapnel shot was quite useless. As a consequence, shrapnel was indeed quite useless in most engagement. You simply couldn't get the timing right. Many fuses weren't even accurate enough if you knew the perfect timing!

Next weak spot: Assuming a good maximum elevation, you'd want to make use of it on more than long range shots. As mentioned before, HE shells produce the best fragmentation patterns if they fall to earth almost vertically. This happens only if they were fired at high elevation angle. Howitzers vary the strength of their propellant charge to make use of this effect even on short ranges. The cannon had fixed ammunition with fixed propellant strength.

Maybe you think that it's not possible to vary the propellant charge in a cannon, but a cannon can be turned into a cannon-howitzer (more usual term is AFAIK gun-howitzer) by simply using semi-fixed cartridges. Those are cartridges where you can detach the case with the propellant, adjust the propellant strength and re-attach the case to the shell again.

Then there's another issue with ammunition: The shells were made of rather soft iron. This produces impressive large fragments, but only few of these and irregularly so. A much better frag pattern is possible with harder steel. This also allows for thinner walls and thus more explosive content and force. Oh, and it would have been possible to add engraving on the interior in order to make the frag pattern even more regular and effective.

Next issue with ammunition; driving bands. Copper driving bands were incredibly expensive, for copper was in short supply. Soft iron proved to be a fine substitute in time for WW2; engineers might have figured this out earlier if more attention would have been paid to the military-economic challenges of industrial warfare before WW1.

Another ammo-related issue: The cases were AFAIK made of brass (copper and zinc). Again, later research yielded perfectly fine lacquered steel cases.

Finally the shell size; due to lack of interest in squeezing out a good range, shells were commonly of a very poor aerodynamic shape. The armies of WW1 only introduced superior shell shapes in about 1917, yielding about 15-20% more range with the same propellant and barrel.

It's astonishing that most reports about ammunition supply shortages in the Germany of 1914/1915 focus on the availability of nitrogen (previously made of imported saltpetre, during the war exclusively made with synthesizers that used the 80% nitrogen in the air). The use of synthesized nitrogen solved the ammunition crisis of 1915, but it also contributed to the famines of 1916 because the agriculture needed nitrogen as fertilizer.

It appears the entire ammunition was about the use of scarce or wrong materials.

- - - - -

Maybe you think they couldn't have done better with the technology of their time, but the ammunition-related issues were all about paying attention to them in the first place and there was in fact a vastly superior gun concept:

It introduced the revolutionary split trail (54° traverse!) and featured a fine maximum gun elevation (not sure if 45° or 65°). This allowed even for a secondary use against aerial targets (most importantly the rather easy shrapnel target of tethered artillery observation balloons).

The difference between a really well-done light field artillery piece and what was in service in the thousands is astonishing. It's yet again a reminder about how poorly even the great powers were prepared for a great war in 1914 after up to 43 years of no involvement in European warfare and just a handful to dozens of expeditionary/colonial wars for two generations.

Now guess what time period does this remind me of?

S O

P.S.: I wrote this in mm instead cm. Not sure what was preferred at the time, maybe cm. "7.7 cm" is still awkward to me, as in German we'd actually write "7,7 cm" and no-one really needs this confusion.

12 comments:

what do we learn? which army can replace their inventory every 15 years? none! did it matter? no! most armies had guns of similar design! btw you missed the point: german shells were einheitsgeschosse. the worst of both worlds. appart from this fk96na was a usefull design augmented by a strong medium artillery it was part of the strongest artillery branch in the world.

and so did the french. the only difference being that the reich was unable to win a long war in the first place. langemarck surely was a failure of german strategy but in a very different way than you imply

which is a function of the mainly defencive stance of french forces. comunications (technology but also procedures) of those days didnt realy suit mobile employment of artillery. this is one aspect of the overall superiority of defence then. the french stocks of ammunition were only marginaly larger.

some problems were a direct result of maintaining large peace time armies, you could not longer replace hardware in the rate of technological developement. (See v. Seeck's plans for the new Reichswehr)

Ammunition production required machinery that was not available in sufficient numbers in 1915/16 and of course chemicals.

To my best of knowledge the low quality of rounds in 1915/16 was a production problem, not a lack of metals.

The Fußartillerie compensated a little bit for weak German Feldartillerie, see the Battles of the Border.

However, most of the problems in 1914/1915/16 could have been avoided by a more careful analysis of insustrial structure. The German army like most of its peers was not good in this department and was bitten by the decision to attack in the west.

First I would like to hint at an excellent book specialized in issues of Industrial Logistics of Germany in WW1 : « La Grande Débrouille » by ret. General Jean-Claude Laparra (YSEC Editions). It is available in french only, but has a great deal of information, cheifly about :recycling of war materialuse of war booty, also adaptation and hybridation (hints at reverse engineering were also made)lean design

About the lack of war materials, there was a lot of experimenting with soft iron, steel etc. before ferrous casings were practical, and it seems they had issues for the durations of war. Another aspect relating to explosives was the use of picric acid, that oxyded with the shell's steel and became very sensitive to shock. The shells exploded when the shot was fired. The laquering of the inner shell eliminated that, but it took a while to find this.

Basing myself on your data, I'm convinced that the 7,7 cm gun was not well conceived in the first place. But issues relating to copper and brass were probably not envisionned at the time of conception. It requires an advanced kind of mind to envision the « life cycle » of a product, whereas it seems the minds of top management is not primarily geared towards these kind of issues. The term « ASAP », or the phrase « you need to do that for yesterday » is a sign of bad anticipation management. Managers try to disguise this as a form of management by stress, but in reality it is just shoddy management. (There are things I witnessed in my experience as business consultant that made me lose all illusions on the matter).

That said, between say 1880 and 1910 the technology was evolving with leaps and bounds. A long life cycle was likely not envisionned, as the development history of this very gun (7,7 cm FK 96) shows. One year after it was introduced, the french « 75 » made it obsolete. An even more telling exemple is a series of austro-hungarian field guns and mountain guns ( http://en.wikipedia.org/wiki/7_cm_Gebirgsgesch%C3%BCtz_M_99 ) that used bronze barrels (special hardened bronze called Eisenbronze, but it could have been propaganda). Such models are made only to bridge a gap. As a matter of fact, the FK96 was itself a modernization of the FK 73 ( http://www.lovettartillery.com/9cm._C_1873_Kanone.html ).

As history showed, the very concept of a field gun was made obsolete during WW1, so there is substance to this argument. In retrospective, the effort saved on the 7,7 cm guns was perhaps meant to be better invested on other issues, like heavy howitzers for instance (if it really was is another matter I won't discuss here).

These kind of shortcomings were seen everywhere at that time. The french had an enourmous amount of 1886 Lebel rifles, that on the one hand allowed them to have enough rifles in the first place, onthe other hand impacted (cartridge) the development of more modern weapons (such as the semi-auto rifle http://en.wikipedia.org/wiki/Fusil_Automatique_Modele_1917 that began in 1913, or the Chauchat LMG).

The British guns had fired 164 to 208 rounds each at Magersfontein (1899), a single battle. It should have been possible to anticipate that bigger ammo stocks were required with quicker firing guns and for a whole war.Ammo stocks are among the hardly visible qualities of an army and thus as important as often neglected.

ammunition stock is only half of the issue. You have to bring the rounds to the guns and here it becomes interesting:

1) Train columns were able to provide supply up to 120 km from the last train station.

2) If the advance, during which a only relative small ammunition transport volume is needed, stalls the necessary transport volume increases dramatically when the attacker tries to soften the defense by artillery.

Result is that the attacker has not only extended or over-extended supply routes but suddenly needs much higher transport volume. This situation clearly favours the defender who can still use railways and has only short distances to cover with horse drawn columns. The attacker need trucks to transport the ammunition or at least horse fodder.

I concur that ammunition stocks and production capacity were too small in 1914, but do not think that the German Feldartillerie was the main problem.

one should add that shells per gun numbers for germany include those of much larger numbers of medium artilery (105 mm). furthermore the arms race of the fin de siecle was interactive increased stocks would have favoured the french strategic position more. its only your everyone-s-stupid-fallacy that leads you to believe the french generals wouldnt have noticed.

note that the fk96na was indeed a political scandal in the german reichstag. the options then were holding onto an obsolete gun for the next decade or accept a slightly inferior gun for a longer time of service.

I doubt it. For one, there were enough attempts and the second reason for my doubts is that serious operational research only began in about 1940. The Americans did misunderstand some HE effects as late as during the 1970's!http://preview.tinyurl.com/83xdkge

The WW1-era graphics on fragmentation effects (known to me) are very crude and inaccurate.